Click here to view fulltext PDF

Permanent link:
https://www.ias.ac.in/article/fulltext/pram/067/01/0199-0205

Ultrashort laser pulses; semiconductor nanostructures; ballistic transport

By suitable design it is possible to achieve quasi-ballistic transport in semiconductor nanostructures over times up to the ps-range. Monte-Carlo simulations reveal that under these conditions phase-coherent real-space oscillations of an electron ensemble, generated by fs-pulses become possible in wide potential wells. Using a two-color pump-and-probe technique we have been able to observe this new phenomenon in excellent agreement with the theoretical predictions. Apart from its fundamental significance, ballistic transport in nanostructures can also be used for high-efficiency coherent THz-sources. The concept of these THz-emitters and its experimental confirmation will also be presented.

G H Döhler^{1 2} M Eckardt² A Schwanhäußer² F Renner² S Malzer^{1 2} S Trumm³ M Betz³ F Sotier^{3 4} A Leitenstorfer^{3 4} G Loata⁵ T Löffler⁵ H Roskos⁵ T Müller⁶ K Unterrainer⁶ D Driscoll⁷ M Hanson⁷ A C Gossard⁷

1. Max-Planck-Research Group of Optics, Information and Photonics, University of Erlangen, Günther-Scharowski-Strasse 1, Bau 24, Erlangen - 91058, Germany
2. Institute of Technical Physics I, University of Erlangen, Erwin-Rommel-Strasse 1, Erlangen - 91058, Germany
3. Physik-Department E 11, Technische Universität München, Garching - 85748, Germany
4. Fachbereich Physik, Universität Konstanz, Konstanz - 78457, Germany
5. Institute of Physics, Johann Wolfgang Goethe University, Max-von-Laue-Str. 1, Frankfurt - 60438, Germany
6. Institut für Festkörperelektronik, Technische Universität Wien, Vienna, Austria
7. Materials Department, University of California, Santa Barbara, CA - 93106, USA

Published

July 2006